Apparatus adapted for the bending of wire strip material and the like



Jan. 20, 1959 s. LARKIN 2,8

APPARATUS ADAPTED FOR THE BENDING OF WIRE STRIP MATERIAL AND THE LIKE Filed June 22, 1956 2 Sheets-Sheet 1 27 0 I 0 A r B c D 0 H94. 5'? w H (-I 1 Q 7 5 15 4" E 19 16 O 6 o IWEmg J4; lam m;

Jan. 20, 1959 s. LARKIN 2,869,591

APPARATUS ADAPTED FOR THE BENDING OF WIRE STRIP MATERIAL AND THE LIKE,

Filed June 22, 1956 2 Sheets-Sheet 2 4g Fi .7

.L'vvavn-e United States Patent APPARATUS ADAPTED FOR THE BENDING OF WIRE STRIPMATERIAL AND THE LIKE Sam Larkin, Belle Harbor, N. Y.

Application June 22, 1956, Serial No. 593,238

1 Claim. (Cl. 140-71) This invention" relates to machines for bending wire, rod and band stock into various shapes and more particularly to a die unit for effecting a single bend. Machines of the class mentioned, comprise a plurality of such die units arranged to operate in a predetermined timed relation. Each die unit includes a pin or mandrel against which the wire to be bent is rested and then acted upon by a movable part of the die to accomplish the required bend. In the present invention, each die apparatus is operated by a powered reciprocating member which causes the die to close to form the bend, opens the die and retracts the mandrel so that the work is free to be acted on by another of the die units. An object of this invention is to provide a noveland improved die unit of the character mentioned, operated by a single powered reciprocating member, which in one stroke in one direction, will close the die, open the die and retract the mandrel. During the return stroke, other dies do their work. Hence the present invention affords a substantial saving in manufacturing time. Heretofore, the greater part of the time lost was the time interval dur% ing change of direction of the stroke rather than the length of stroke. In the present invention, the work is released before there is a change of direction of the powered die-operating member. i it i Another object of this invention is to provide a novel and improved bending die mechanism of the type set forth, having a new mode of operation. i A further object thereof is to provide a die unit of the character described, of novel and improved construction, which is reasonably cheap to make, easy to'use and efficient in carrying out the designed.

Other objects and advantages will become apparent as this disclosure proceeds. i

For the practice of this invention,,one form it may assume consists of a lengthwise slidably mounted pin or mandrel against which the wire to be worked on, is rested. There is a movable die part, shiftable towards purposes for which it is and away from said mandrel. The powered reciprocating member may be the piston rod of a. double-acting air cylinder. This piston rod acts on a toggle to shift the movable die member towards and then away from the mandrel. To do this, the toggle linkage passes through dead center. Said piston rod also acts on a linkage to retract the mandrel at the change of direction of the movable die part. Provision of a lost motion construction interposed in the latter linkage, serves to hold the mandrel at rest while the movable die part approaches the mandrel. The closing of the die, followed by its opening and the retraction of the mandrel, occur during a single stroke of the piston rod in one direction. During such single stroke, the bend in made and thework is released. During the return stroke of the piston rod, the work is free to be worked on by another die unit or units. The period of such return stroke is not within manufacturing time, neither is the time the reversal of piston rod travel.

it takes for r In the accompanying drawings forming part of this specification, similar characters of reference indicate corresponding parts in all the views.

Fig. 1 shows the face of a plate which serves as the frame. On it are shown a plurality of die units embodying the teachings of this invention. All linkages are omitted in this view in order to attain clarity 'of illustration. A straight wire is shown rested across the pins of the die units; such pins being the mandrels. 1

Fig. 2 shows the wire bent into a rectangular ring form having rounded corners. The apparatus shown in Fig. 1, was used to do this work as will be explained.

' Fig. 3 is a magnified view of a part of Fig. l, including one of the die units.

Fig. 4 is a section taken at lines 44 in Fig. 3.

Fig. 5 shows another wire form capable of being made with the apparatus shown in Fig. 1, when slightly modimake the work shown in Fig. 5.

Fig. 6 shows the mandrel and the movable die part which co-acts therewith to form the bends required to I Fig. 7 shows another wire form capable of being made with the apparatus shown in Fig. 1, when slightly modified. i Fig. 8. shows the mandrel and movable die part used to make the work shown in Fig. 7.

In the drawings showing one form this invention may assume, the numeral 15 designates a frame which may,

be a plate on which a plurality of bending die units are mounted. All such units A, B, C and D being identical, the description of one will sutlice for each of them. Such unit comprises apin or mandrel 16 extending through the plate 15 and is longitudinally slidable; On the front surface of said plate there is a bearing 17 for the slidably mounted tool 18. Upon movement of said tool towards the mandrel 16, both Will cooperate, to bend a wire 19 between them in. a manner determined by said members 16 and 18 acting as a die. A double-acting pneumatic cylinder 20 is carried on the back of the plate onsuitable supports 14. The piston rod 21 of said cylinder extends through said plate and at its free end at 22,. has pivotally secured thereto one of the ends of each of the links 23;

. at a point intermediate the ends of such lever.

24 whichare of equal length. The other end of the link 23 is pivotally connected at 25 to the. die tool 18, while theother end of the link 24 is pivotally connected at 26 to a lug 27 which is fixed on the plate 15. A lever 28 is pivotally mounted intermediate its ends at 29 to a standard 30 fixed to the plate 15; such standard being between the mandrel 16 and the piston rod 21, on the back of said plate; A lever 31 positioned in the open ing 32 in the plate, is pivotally mounted at 33 to the plate, This pivotal connection 33 is between the standard 3i) and the piston rod 21. The ends of the two levers 28,31, which arenearest each other, are pivotally connected to the ends of anintermediate link34, respectively. The other end of lever 28 is formed with a slot 28 longitudinally. of such lever, which slidablyengages the pin 16 which extends laterally from the mandrel 16. The other end of of the lever 31 is provided with atransverse slot 31' along the piston rod 21, through which slot, the pin 21' protruding laterally from said rod, extends and is slidable placed between them. The mandrel 16 ext-ends forward of the plate 15. The pin 21 is in contact with the left end of the slot 31. The links 23, 24 constituting a toggle are in obtuse angle relation in front of the plate 01' frame T pe t t e die u a r h w 9 is s t is place, the cylinder 2t? is actuated whereuponits piston moves to the right. During the first half of such piston travel, the links 2 3, 24 will assume alignment, whereupon thetool 18 will move towards the mandrel 16 and wire 19 will be bent and pin 21' moving with the piston rod 21, will slide along the slot 31' and contact the right end of such slot. Up to this time the linkages 31, 34, 28 and the mandrel 1o will be at rest; said slot 31' serving as a lost motion means. During the second half of such piston travel to the right, the links 23, 24 will enter the opening 32 and will assume an angular relation whereupon the tool 18 will move away from the mandrel 16 and simultaneously, the pin 21 will shift the lever 3;

' whereby the mandrel 16 will retract away from the front of the plate and the work will be entirely free. Now, upon working the cylinder to cause the return stroke of its piston, the die unit will at the end ofrsuch return stroke, 'be again in initial rest condition ,as shown in Fig."4. The numeral 24' denotes a slot in link 24, to permit the movement of such link.

The nature of the work to be done, will of course determine the number of die units to be employed, their relative positioning on the frame and the timed relation in which they are to be operated. For example, if it be desired to make a rectangular wire ring or hoop 40 with rounded corners 41, 42, 43, 44 as shown in Fig. 2, then, the bending machine therefor may be as, shown in Fig. 1, where four bending units aroused. The respectively cooperating mandrels 16 and the tools 17, are of proper contour to make the required bends. After the required length of wire 19 is positioned to rest against the mandrels 16 (the units A, B, C and D being in rest condition as shown in Fig. 1), the units A and D are operated. This will accomplish the bends 41 and 42 and the tools 18 of said die units A and D will move away from their respective mandrels 16 and such mandrels will be retracted. All this occurs during the single stroke of the pistons of' the air cylinders associated with said die units A and D. At the end of such stroke, the work is restingagainst the mandrels of the die units B and C and is of course free from any interference from the retracted mandrels of the die units A and D. Now, the die units B and C are operated whereupon the bends 43 -and,44 are accomplished during one stroke of the pistons of the air cylinders of the said die units B and C, and of course, there follows the retraction of the mandrels of said units B and C. Whereupon the finished hoop i-i) is automatically discharged because nothing holds it. All air cylinders are nowoperated to cause return'stroke of their respective pistons, whereupon all die units assume normal rest condition as shown in Fig. 4. The machine is now ready to receive the next length of Wire to be worked on.

' -A further saving in manufacturing time can be effected by having the initial condition where the die units A and D are as in Fig. 4, While the condition of the die units B and C are at the end of a cylinder stroke sothat the pistons of the units A and D are at the left in Fig. 4, while those of the units B and Care at right. The mandrels ofthe die units A and D areexposed, while the mandrels of the die units B and C are retracted. After setting the wire against the mandrels of the units A and B, all four die units are then operated simultaneously. The bends 41 and 42 will have been made thereby, the mandrels of the die units B and C will come forward in the first half of such stroke and the mandrels of the die units A and D will retract during the second half of snch stroke. Now, all four die units are again operated simultaneously, whereupon the bends 43 and 4dare accomplished, the mandrels of the die .units' B and C are retracted and the mandrels of the die units A and Bare brought forward. This saves the time of half a stroke per cycle of operation to make one hoop, and further,

reversal of stroke in inactive die units occurs during bending operation being performed by the other die units.

Messiaen, the time "interval for reversal of stroke is not included in manufacturing time. The work is free for removal after the bending accomplished by the die units B and C. All this is possible because the die units are in identical open condition at the beginning and at the end of each piston stroke, regardless of its direction. Although the hoop is rectangular, the dies are set to effect an overbend by having them in angular relation, as shown, instead of true parallel, in order to take care of the springiness of the work material.

Different shapes of work will of course require appropriate dies, meaning the cooperating die parts which determine the shape of the bend. A die unit suitable for accomplishing the type of bend shown at the corners of the hoop 4t), is shown in Fig. 6 where the numeral :37 indicates the mandrel and numeral d8 denotes the movable die.pa1t. A die unit suitable to make the corner bend 49 in the hoop shown in Fig. 7, is illustrated in Fig, 8 where the mandrel is shown at St and its associated movable die part is indicated by the numeral 51.

. it is evident that each die unit may be a separate unitary structure to be mounted on a main frame in any desired arrangement dependent upon the article to be manufactured and that provision can be made to change the cooperating die parts. All this is readily understandable to those versed in the machine art without further illustration. Likewise, means to control the operation of the plurality of die units in any desired timed. relation, is well known in the'machine art and needs no further explanation or showing. This invention teaches the novel and improved die unit, one form of which is shown in the Figs. 3 and 4 herein. It is the novel teachings as to the die units, that protection is sought for.

This invention is capable of various forms and nu- .merous applications without departing from the essential features herein disclosed. It is therefore intended and desired that the embodiment shown herein be deemed illustrative and not restrictive and that the patent shall cover all patentable novelty herein set forth; reference being had to the following claim rather than to the spe% cific showing and description herein to indicate the scope of this invention.

I claim:

In an apparatus adapted for bending wire, a frame, a mandrel in initial rest position, having a portion thereof projecting from the frame; said mandrel being movably mounted on the frame whereby it is shiftable to retract substantially to the plane ofthe frame it projects from in its initial position, a die part mounted on the frame for movement thereon towards and away from the said 1 projecting part of the mandrel whereby a wire placed die part will be contacted by both of them when said diepart is moved toward said projecting mandrel part while the mandrel is in its initial rest position; said mandrel and die part constituting a bending means for the wire; said die part beingaway from said projecting part of the mandrel when said mandrel is in its initial rest position, an operating member mounted for rec'iprocatory-like movement on the frame, a first linkage means for shifting the die part associated with said operating member and die part; said first linkage means comprising a pair of links; one end of each of such links being pivctally connected to the-operating member; the other end, of one of said links being pivotally connected to the die part;

the other end of the other of said links being pivotally connected to the framejthe last mentioned link'being slidable at one of its pivotal connections; said links being in alignment at a time between at commencement and end of travel of the operating member in each direction V respectively and in angular relation at each commencement and end of travel of said operating member in each direction respectively, a second linkage means for shifting the mandrel associated' with said operating member and the mandrel; said second linkage means comprising a first lever swingably mounted intermediate its ends on the frame; one end of such first lever being pivotally associated with the mandrel, a second lever swingably mounted intermediate its ends on the frame; one end of such second lever being pivotally associated with the operating member; the other ends of said levers being pivotally linked and a last motion means interposed in said second linkage means; said lost motion means constituting a pin serving as one of the pivotal connections away from the axes of swing of said levers, and one of the parts connected by such pin, having a slot along the line of movement of the operating member; said pin extending through such slot and fitted for slidable movement along said slot; said pin being at one end of said slot when the mandrel is at its initial rest position and at the other end of said slot when the said pair of links are in alignment, whereby on movement of the operating member in one direction, during the first part of such move ment, said operating member will operate the first linkage means whereupon the die part will be moved towards the projecting part of the mandrel and the lost motion means will maintain the second linkage means at rest and during the remainder of such movement of the operating member in said one direction, said operating member will operate the first linkage means whereupon the die part will be moved away from said projecting part of the mandrel and said operating member will operate the second linkage means whereupon the mandrel will be retracted and then, upon movement of said operating memher in the opposite direction, during the first part of such movement in such opposite direction, the operating memher will operate the first linkage means whereby the die part will be moved towards the mandrel and the operating member will operate the second linkage means whereby the mandrel will return to initial rest position and during the remainder of said movement of the operating member in such opposite direction; said operating member will operate the first linkage means whereby the die "part will move away from the mandrel and the lost motion means will maintain the second linkage means at rest.

References Cited in the tile of this patent UNITED STATES PATENTS 2,408,379 Day Oct. 1, 1946 FOREIGN PATENTS 28,387 Great Britain Aug. 22, 1904 347,942 Great Britain May 7, 1931 

